Shower pan

ABSTRACT

A pre-fabricated shower pan provides the features of a custom on-site constructed shower pan. The pre-fabricated shower pan comprises a wood frame, a drain, a sloped floor, and a hot-mopped tar covering. A box is constructed from a four by six dam on one or two sides, one by six lumber on the remaining sides, and a plywood floor. A drain is mounted in the center of the plywood floor. The sloped floor is created by layers of composition shingles or similar material. Tar is mopped over the shingles and on the inside of the box to provide a watertight seal. The tar may further be mopped over part or all of the outside of the box.

BACKGROUND OF THE INVENTION

The present invention relates to shower construction and in particular to a pre-fabricated shower pan.

Many homes, offices, and businesses include bathrooms or restrooms with showers. While pre-fabricated single piece shower liners are available, many prefer a more custom built tile shower interior. Generally, such custom shower interiors are built by first framing the shower, then building a shower pan in the base of the shower, and then completing the shower. The step of building the shower pan includes constructing an enclosed base, laying a felt-like material inside the enclosed base, and mopping hot tar over the felt. The sloped floor may be formed later using concrete, and tile is laid over the concrete. While very good results are provided by these steps, the method is tedious and unpleasant. The tar is heated to over 400 degrees Fahrenheit for mopping and produces fumes and heat, generally in an enclosed working area.

BRIEF SUMMARY OF THE INVENTION

The present invention addresses the above and other needs by providing a pre-fabricated shower pan which provides the features of a custom on-site constructed shower pan. The pre-fabricated shower pan comprises a wood frame, a drain, a sloped floor, and a tar covering. A box is constructed comprising a four by six dam on one or two sides, one by six lumber on the remaining sides, and a plywood floor. A drain is mounted in the center of the plywood floor. The sloped floor is created by layers of composition shingles or similar material. Tar is mopped over the shingles and on the inside of the box to provide a watertight seal. The tar may further be mopped over part or all of the outside surface of the box.

In accordance with one aspect of the invention, there is provided a prefabricated shower pan. The shower pan includes a box having a plywood floor, at least one solid wood dam attached to the floor, at least one solid wood side wall attached to the floor, and a solid wood rear wall attached to the floor. A shower pan interior defined by a top surface of the floor and inside surfaces of the walls and the dam. A drain is attached to the floor approximately centered on the floor. Composite roofing or similar material is laid on the floor creating a slope from the dam and walls downward to the drain and composite shingle material over the material. Hot mopped tar is applied over the composite shingle material to provide a water tight surface

In accordance with another aspect of the invention, there is provided a method for constructing a pre-fabricated shower pan. The method comprises providing a floor, cutting a drain hole in the floor, attaching a dam to a front edge of the floor, side walls to the dam and to side edges of the floor, and a rear wall to the side walls and to a rear edge of the floor. A drain is attached to the floor, residing in the drain hole. A sloped layer of a filler material is laid on the floor between the dam and walls and the drain to create a sloped floor sloping downward towards the drain. The interior surfaces on the floor, dam, and walls are hot mopped with tar.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:

FIG. 1 shows a prefabricated shower pan according to the present invention attached to studs for constructing a shower.

FIG. 2 is a detailed perspective view of the prefabricated shower pan.

FIG. 3A is a top view of the prefabricated shower pan.

FIG. 3B is a side view of the prefabricated shower pan.

FIG. 4 is a cross-sectional view of the prefabricated shower pan taken along line 4-4 of FIG. 3A.

FIG. 5 is a wide second embodiment of the shower pan.

FIG. 6 is a third embodiment of the shower pan having two dams.

Corresponding reference characters indicate corresponding components throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims.

A prefabricated shower pan 10 according to the present invention is shown attached to studs 12 for construct a shower. The studs 12 include notches 14 to accept the shower pan 10.

A detailed perspective view of the prefabricated shower pan 10 is shown in FIG. 2. The prefabricated shower pan 10 comprises a drain 16, side walls 18, a rear wall 20, a dam 22, and a floor 24. The prefabricated shower pan 10 further is coated with a moister sealing material, and is preferably covered by hot mopped tar. The tar may be mopped onto the inside surfaces of the shower pan and the top surface of the dam, or the entire shower pan, excluding the drain, may be covered in tar. The tar is preferably approximately ¼ inches thick and the notches 14 are preferably approximately one inch deep to accommodate the thickness of the tar plus the thickness of the side walls 18 and rear wall 20.

A top view of the prefabricated shower pan 10 is shown in FIG. 3A and a front view of the prefabricated shower pan 10 is shown in FIG. 3B. A cross-sectional view of the prefabricated shower pan is taken along line 4-4 of FIG. 3A. The floor 24 is preferably made from plywood and is preferably approximately 40.25 inches by 49.5 inches, and is preferably approximately ¾ inches thick. The floor 24 may alternatively be a manufactured material of similar dimensions. A hole is cut in the approximate center of the floor 24 for the drain 16. The walls 18 and 20 are preferably one by six solid lumber finished on four sides, for example, ¾ inches actual thickness. The side walls 18 are preferably approximately 40.25 inches long and the rear wall is preferably approximately 48 inches long. The dam 22 is preferably four by six solid lumber finished on four sides (S4S), for example, 3.75 inches actual thickness and 5.75 inches actual height, and is preferably approximately 48 inches long. The dam 22 may alternatively be constructed from thinner lumber, for example, five layers of one by six S4S lumber (each of which layer of one by six S4S lumber is approximately ¾ inches thick.)

The dam 22 is preferably attached to the floor 24 by 6D (i.e. 6 penny) nails (for example an approximately two inch long and approximately 0.120 inch diameter nail) and wood glue with the outside face 22 a of the dam 22 even with a corresponding edge of the floor 24. The walls 18 and 20 are preferably attached to the dam 22 and to the floor 24 by 6D nails and wood glue with the outside faces 18 a and 20 a of the walls 18 and 20 even with corresponding edges of the floor 24.

A cross-sectional view of the shower pan 10 taken along line 4-4 of FIG. 3A is shown in FIG. 4. The interior of the prefabricated shower pan 10 includes a filler for forming a slope towards the drain 16. The filler preferably comprises a floor layer 28 a of composite shingle material laid over the floor 24. Additionally, a wall layer 28 b of the composite shingle material may be laid against inside faces 18 b and 20 b of the walls 18 and 20, and inside face 22 b of the dam 22. A slope is created by the floor layer 28 a, which slopes downward from the walls 18 and 20 and dam 22 toward the drain 16, wherein the slope is preferably created by varying a number of layers of composite shingle material.

The drain 16 is preferably an instaset drain (i.e., a two-piece hot mop shower pan drain), and is preferably made from cast iron. The drain 16 is preferably attached to the floor 24 by an adhesive which is preferably heavy duty liquid nails, and is sealed to the floor 24 using a mastic. Weep holes 17 in the drain 16 are exposed above the filler.

The shower pan 10 (see FIG. 3A) preferably has outside dimensions of approximately 36 inches by approximately 40 inches. A wider second embodiment 10 a of the shower pan is shown in FIG. 5 having a longer rear wall 20 a and a longer dam 22 a. The shower pan 10 a may have outside dimensions of approximately 36 inches by approximately 60 inches. A third embodiment 10 b of the shower pan having two dams 22 c and 22 b is shown in FIG. 6.

A method for constructing the shower pan 10 is described in FIG. 7. The method comprises providing a floor at step 60, cutting a drain hole in the floor at step 66, attaching a dam to a front edge of the floor at step 64, attaching side walls to the dam and to side edges of the floor at step 66, attaching a rear wall to the side walls and to a rear edge of the floor at step 68, attaching a drain to the floor, the drain residing in the drain hole at step 70, laying a filler on the floor between the dam and walls and the drain to create a sloped floor sloping downward towards the drain at step 72, and covering interior surfaces on the floor, dam, and walls with a water proof sealant at step 74. The step of covering interior surfaces preferably comprises hot mopping the interior surfaces.

The shower pan 10 of the present invention is constructed to allow a simple connection of the drain 16 to stub drain pipe under the installed shower pan. A method for connecting is described in FIG. 8. The method includes cutting notches in studs to accept a shower pan at step 80, positioning the shower pan in the notches at step 82, fixing the shower pan to the studs at step 84, removing a drain grating at step 86, applying glue to a length of pipe at step 88, inserting the pipe into the drain and into a coupling residing below the drain at step 90, and tightening a fitting in the drain around the pipe to form a seal at step 92. The length of pipe is preferably a length of PVC pipe, and is preferably approximately seven inches long. The pipe is preferably sealed to the drain by tightening a caulking nut in the drain which expands a rubber gasket to form a seal between the drain and the pipe.

While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims. 

1. A prefabricated shower pan comprising: a box comprising: a floor; at least one dam attached to the floor; at least one side wall attached to the floor; and a rear wall attached to the floor; a shower pan interior defined by a top surface of the floor and inside surfaces of the walls and the dam; a drain approximately centered on the floor; a filler on the floor creating a slope from the dam and walls downward to the drain; and a waterproof coating applied over the inside surface.
 2. The shower pan of claim 1, wherein the floor is plywood.
 3. The shower pan of claim 1, wherein the walls are solid wood walls.
 4. The shower pan of claim 1, wherein the dam is a solid wood dam.
 5. The shower pan of claim 1, wherein the filler comprises layers of composite shingles.
 6. The shower pan of claim 5, wherein the filler includes layers of composite shingles forming a slope.
 7. The shower pan of claim 1, wherein the drain is an instaset drain.
 8. The shower pan of claim 1, wherein the drain is a two-piece hot mop shower pan drain.
 9. The shower pan of claim 1, wherein the waterproof coating is hot-mopped tar.
 10. The shower pan of claim 1, wherein: an outside face of the dam is even with a corresponding edge of the floor; and outside faces of the walls are even with corresponding edges of the floor.
 11. A prefabricated shower pan comprising: a box comprising: a plywood floor; at least one solid wood dam attached to the floor; at least one solid wood side wall attached to the floor; and a solid wood rear wall attached to the floor; a shower pan interior defined by a top surface of the floor and inside surfaces of the walls and the dam; a drain approximately centered on the floor; layers of composite shingles on the floor creating a slope from the dam and walls downward to the drain; and hot mopped tar applied over the inside surface and a top surface of the dam.
 12. A method for constructing a pre-fabricated shower pan, the method comprising: providing a floor; cutting a drain hole in the floor; attaching a dam to a front edge of the floor; attached side walls to the dam and to side edges of the floor; attaching a rear wall to the side walls and to a rear edge of the floor; attaching a drain to the floor, the drain residing in the drain hole; laying a filler on the floor between the dam and walls and the drain to create a sloped floor sloping downward towards the drain; covering interior surfaces on the floor, dam, and walls with a water proof sealant.
 13. The method of claim 12, wherein covering interior surfaces on the floor comprises covering interior surfaces on the floor while leaving weep holes of the drain uncovered.
 14. The method of claim 13, wherein covering interior surfaces on the floor, dam, and walls with a water proof sealant comprises covering interior surfaces on the floor, dam, and walls with hot mopped tar.
 15. The method of claim 14, further including cover the outside surfaces of the shower pan with hot mopped tar.
 16. The method of claim 12, further including installing the shower pan comprising the steps of: cutting notches in studs to accept the shower pan; positioning the shower pan in the notches; fixing the shower pan to the studs; removing a drain grating; inserting a length pipe into the drain and into a coupling residing below the drain; and tightening a fitting in the drain around the pipe to form a seal.
 17. The method of claim 16, further including applying glue to the length of pipe before inserting the length pipe into the drain and into the coupling. 